Graphene, the material made of a single layer of carbon atoms, may be a step closer to reaching its potential: IBM researchers announced that they have created the first graphene integrated circuit.

In the seven years since its creation, graphene has been praised as the marvelous material that will make cellphones and other electronics even smaller, thinner and faster. The graphene revolution has happened in incremental steps, but this week IBM engineers announced a significant one: They published a paper in Science announcing that they have built an integrated circuit using graphene, bringing graphene-based technology closer to reality.

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Graphene is a two-dimensional solid made up of a single layer of carbon atoms. Andre Geim and Konstantin Novoselov won last year's Nobel Prize in physics for isolating it in 2004. In the seven years since, research into the practical applications of this new material has expanded explosively. People are interested in graphene not only for its small size, but also because of its ability to swiftly transfer information. The arrangement of carbon atoms in graphene causes the material to have a very high electron mobility, meaning that electrons within the material can move at very high speeds, potentially speeding up communication times.

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The circuit that study co-author Yu-Ming Lin and other IBM researchers built is an integrated circuit, meaning that all the components of the circuit are concentrated into one place—just as they are on a computer chip. "If you really want to have a high-performance device like your cellphone, you need an integrated circuit," Lin says.

Previously, circuits that had graphene components were bulky, with different elements of the circuit connected to one another via wiring. The connections between these devices often degraded the signal running through the circuit, making the circuit less effective, in addition to being relatively large. In the context of circuitry, "large" can mean a range of just centimeters. By contrast, the integrated circuit that the IBM team built is less than 1 square millimeter in size. "In a circuit, size matters," Lin says.

IBM's integrated circuit is designed to function as a frequency mixer. "A frequency mixer is one of the most important circuits used for wireless communications," Lin says. Mixers are devices that take in radio frequency signals and mix them together, emitting a different frequency at the end. This conversion is an important part of any modern communications network, turning radio frequency signals into sounds and information. These mixer circuits are used in radios and phones, and were used in analog televisions before the United States switched to digital broadcasting in 2009.

"The graphene function here is a transistor that can modulate a signal," Lin says. And the researchers' circuit operated at 10 Ghz, a capacity greater than that of most cellphones today. The circuit also worked at very high temperatures, an important aspect in any computer system in which heat can severely limit a computer's performance.

"This work is a milestone," Alexander Balandin says. Balandin is the head of the Nano-Device Laboratory at University of California Riverside, and has been researching the properties of graphene for some time. But while the development of a graphene integrated circuit holds great promise for the communications industry, graphene still has a long way to go before it is usable as a component of computer systems.

"At this point, graphene has this one major drawback," Balandin says: "You cannot turn it off completely." Turning it off is important for transmitting information digitally, in which data is sent in on-off patterns (the zeros and ones of basic computing). Without this ability, graphene's small size and high electron mobility remain useless to researchers designing computer chips and central processing units, according to Carl Ventrice, a researcher at the College of Nanoscale Science and Engineering at the University at Albany. "The holy grail would be if you could integrate graphene into the CPU," he says. It hasn't been done yet, but this week graphene may be one step closer to the digital world.